Automotive engine designers have used a variety of schemes to handle the flow of blowby gases originating in the crankcase of the engine. A scheme disclosed in a February, 1992 Society of Automotive Engineers ("SAE") publication titled "Cosworth MBA Engine" includes a hollow, ported balance shaft which centrifugally separates oil from the crankcase gases. The system shown in the SAE publication does not produce any pumping action of its own but merely relies upon the suction produced by the induction process to move the blowby gases through the separator.
The present invention solves the problem of preventing excessive lubricating oil from passing through the crankcase ventilation flow of the engine while at the same time obviating the need for an additional mechanism such as a balance shaft. The present system provides a powered oil separator without the need for additional gears, shafts, motors, or other devices, and it is suitable for use with engines having camshafts mounted either interior to, or externally of the cylinder block.
According to one aspect of the present invention, a ventilation system for an automotive engine having a crankcase, an induction system, a crankshaft, and at least one camshaft driven by the crankshaft, includes processor means for pumping gases from the crankcase and for separating entrained lubricating oil from the pumped gas flow, with the processor means including a blower operatively associated with the camshaft. The blower works in concert with intake manifold vacuum to move blowby gases into the engine's air inlet. A system according to this invention also includes recovery means for introducing the separated gas into the induction system and for returning the separated oil to the crankcase.